scholarly journals Energy transformation without using filter on high resistive load

2020 ◽  
Vol 40 (1) ◽  
pp. 39-42 ◽  
Author(s):  
Erol Can

In this paper, 9-level, 17-level, 19-level, 21-level, 27-level, and 39- level inverters with SPWM are presented. According to a switching function, the high-multilevel inverter design has been described since a new multi-level inverter structure is considered. The multilevel inverter structure is designed with placing switches and sources on levels. Pulse width modulation, controlling switches in the inverter structure, is also produced by comparison between triangles and sinus signals. Operating sequences of the switches are given in the table in order to demonstrate the inverter operation characteristic with the produced signals. Then, mathematical equations are formed by considering an operation of switches on the load. In simulations and experiments, the 9-level, 17- level, 19-level, 21-level, 27-level, and 39-level inverters are performed on the resistance (R) and inductance (L) loads with different resistance, because it is difficult to generate current and voltage with an acceptable harmonic distortion on the impedances which have high ohmic values. After applications of experimentation and simulation, the obtained results are compared with other published papers of results and the international IEEE standard, which is 5% for harmonic distortions of creating currents and voltages.

Author(s):  
Sasmita Behera ◽  
Matruprasad Jyotiranjan

Wind is a source for generating clean and economical electrical energy with a proper harnessing mechanism. For a wind energy conversion system (WECS), maximum power extraction with optimum power quality is required. In this article, the grid power quality is enhanced, using a multilevel inverter which provides smoother and pure sinusoidal waves as compared to two-level inverter by decreasing total harmonic distortion (THD) in WECS with a permanent magnet synchronous generator (PMSG). Also, a maximum power point tracking (MPPT) algorithm is based on an optimal torque controller, employed to extract more power. In this study, a WECS with a PMSG connected to the local linear resistive load and grid is considered for simulation. A multilevel inverter grid interface is controlled by in phase disposition pulse width modulation (IPD – PWM). The multilevel inverter with MPPT has been acknowledged as superior to a normal two-level inverter without MPPT Controller. Simulation results as observed for fixed and variable wind speed including MPPT demonstrate benefits of the proposed method.


2022 ◽  
Vol 4 (1) ◽  
pp. 1-13
Author(s):  
Madhu Andela ◽  
Ahmmadhussain Shaik ◽  
Saicharan Beemagoni ◽  
Vishal Kurimilla ◽  
Rajagopal Veramalla ◽  
...  

This paper deals with a reduced switch multi-level inverter for the solar photovoltaic system-based 127-level multi-level inverter. The proposed technique uses the minimum number of switches to achieve the maximum steps in staircase AC output voltage when compared to the flying capacitor multi-level inverter, cascaded type multilevel inverter and diode clamped multi-level inverter. The use of a minimum number of switches decreases the cost of the system. To eliminate the switching losses, in this topology a square wave switch is used instead of pulse width modulation. Thereby the total harmonic distortion (THD) and harmonics have been reduced in the pulsating AC output voltage waveform. The performance of 127-level MLI is compared with 15 level, 31-level and 63-level multilevel inverters. The outcomes of the solar photovoltaic system-based 127-level multi-level inverter have been simulated in a MATLAB R2009b environment.


2018 ◽  
Vol 7 (3.1) ◽  
pp. 42
Author(s):  
B Kandavel ◽  
G Uvaraj ◽  
M Manikandan

This paper presents comparative study of Total Harmonic Distortion (THD) and its individual harmonic contents without grid and with grid for Diode clamped multi level inverter (DCMLI) and Flying capacitor clamped multilevel inverter (FCMLI) based Doubly Fed Induction Generator (DFIG) employing PI and Fuzzy logic controller (FLC). Simple method to control for a variable speed wind energy conversion system with a DFIG is connected to the grid through a diode rectifier and a diode clamped multilevel inverter (DCMLI). The DC-link voltage is controlled through a DC-DC boost converter to keep the DC voltage at constant value. Inverter is controlled by sinusoidal pulse width modulation technique, which supplies power to the grid. The THD and its harmonic content are studied for different wind speeds. DFIG fed flying capacitor multi level inverter (FCMLI) based WECS connected to load as well as grid. FCMLI is controlled through sinusoidal pulse width modulation. Voltage and current harmonics are studied. The results of both multilevel inverters are compared. It shows that the level of harmonic content of two types of multilevel inverters working at different wind speeds indicates that Total Harmonic Distortion (THD) for DCMLI has given best results.  


Author(s):  
Kureve D. Teryima ◽  
Goshwe Y. Nentawe ◽  
Agbo O. David

<p>This paper proposes a switching control for a cascaded H-bridge inverter structure with reduced switches which is used to improve the THD performance of a single phase five level CHB MLI. The multi level inverter is simulated for the conventional carrier overlapping APOD and the proposed carrier overlapping APOD Pulse Width Modulation (PWM) switching control technique. The total harmonic distortion (THD) of the output voltages are observed for both PWM control techniques. The performance of the symmetric CHB MLI is simulated using MATLAB-SIMULINK. It is observed that the proposed carrier overlapping APODPWM provides output with relatively low THD as compared to the conventional carrier overlapping APODPWM.</p>


Author(s):  
Bolla Madhusudana Reddy ◽  
Y. V. Siva Reddy ◽  
M. Vijaya Kumar

<p><span lang="EN-US">This paper proposes a new optimal high level multilevel inverter with minimum number of components. This multi level inverter (MLI) is designed with series combination of basic units which can generate positive levels at output. DC source values applied for each basic unit is different with another. An H bridge is connected across proposed MLI for generating negative levels along with positive levels at output and that inverter considered as proposed high level optimal multilevel inverter. Single unit is responsible producing 21 levels. Therefore six units are connected in cascaded form to increase number of levels as 127 at output. Decrease in the number of power switches, driver circuits, and dc voltage sources are the improvement of the proposed MLI. Sinusoidal multiple pulse width modulation (SPWM) technique is implemented to produce pulses for turning ON switches according requirement. Low total harmonic distortion at output voltage or current production is major advantage of proposed module. The validations of proposed MLI results are verified through MATLAB/SIMULINK.</span></p>


The main purpose of this work is to use a fifteenstage diode clamped multi-level inverter that is able to control the speed of an induction motor. To get reduced synchronization and high quality sine curve output voltage. The proposed plan for the diode clamped multilevel inverter is controlled using multicarrier SPWM control. An open circle speed control can be accomplished by utilizing the V/ƒ strategy. This strategy can be executed by changing the recurrence utilized in the three-stage induction motor at the stock voltage and the consistent rate. The proposed system, which results in a poor driver performance, is a useful alternative to the conventional method with high transient losses. Simulation depicts an improved drive performance by reducing the Total Harmonic Distortion resulting from the simulation and effectively controlling the motor speed.


Author(s):  
Kureve D. Teryima ◽  
Goshwe Y. Nentawe ◽  
Agbo O. David

This paper proposes a switching control for a cascaded H-bridge inverter structure with reduced switches which is used to improve the THD performance of a single phase five level CHB MLI. The multi level inverter is simulated for the conventional carrier overlapping APOD and the proposed carrier overlapping APOD Pulse Width Modulation (PWM) switching control technique. The total harmonic distortion (THD) of the output voltages are observed for both PWM control techniques. The performance of the symmetric CHB MLI is simulated using MATLAB-SIMULINK. It is observed that the proposed carrier overlapping APODPWM provides output with relatively low THD as compared to the conventional carrier overlapping APODPWM.


2015 ◽  
Vol 15 (2) ◽  
pp. 229
Author(s):  
P. Sureshpandiarajan ◽  
S.P Natarajan ◽  
C.R. Balamurugan ◽  
K. Ramasamy

<p class="IEEEAuthorAffiliation">This work presents the comparison of various Pulse Width Modulation (PWM) techniques for the chosen single phase half bridge FCMLI (Flying Capacitor Multi Level Inverter). In this paper, a single phase half bridge flying capacitor multilevel inverter is controlled with sinusoidal, THI (Third Harmonic Injection), Trapezoidal and TAR (Trapezoidal Amalgamated Reference)reference with Equal Amplitude Carriers (EAC) and UEAC (Un Equal Amplitude Carriers). The proposed EAC and UEAC is applied for various PWM strategies. The PWM methods used for the analysis are PD (Phase Disposition) PWM, POD (Phase Opposition and Disposition) PWM, APOD (Alternative Phase Opposition and Disposition) PWM and CO (Carrier Overlapping) PWM with EAC and UEAC. For all the PWM methods and references the UEAC produces less THD and higher fundamental RMS (Root Mean Square) values except for m<sub>a</sub> =1. For m<sub>a</sub> =1 the EAC provides less THD (Total Harmonic Distortion) and higher fundamental RMS (Root Mean Square) values for all the PWM methods and references. To validate the developed technique, simulations are carried out through Power System Block Set.</p>


2015 ◽  
Vol 16 (3) ◽  
pp. 520
Author(s):  
Mohammed Rasheed ◽  
Rosli Omar ◽  
Marizan Sulaiman

Cascaded H-Bridge multilevel inverter has become more attractive to generate high power in an electrical distribution system. This paper discusses the control of five level cascaded H-bridge multilevel inverter with super capacitor as a Dc energy storage. The control of the multilevel inverter using PI and space vector pulse width modulation (SVPWM) controllers based on the modelling and Simulink of cascaded H-bridge can observe the effectiveness of the proposed control to reduce harmonic contents of the multilevel inverter output. High frequency ripple from the inverters can be removed from the system using low voltage filter. Total harmonic distortion (THD) for both current and voltage is quite low to meet the IEEE standard. Modelling of the system has been done using MATLAB/Simulink.


Author(s):  
C. R. Balamurugan ◽  
S. P. Natarajan ◽  
T. S. Anandhi ◽  
B. Shanthi

For high power applications Multilevel Inverter (MLI) is extensively used. The major advantages of MLI are good power quality, low switching losses and maintenance of the desired voltage. In this work, the three phase cascaded multi level inverter is analyzed under various modulation techniques that include Sub-Harmonic Pulse Width Modulation (SHPWM) i.e. Phase Disposition (PD) strategy, Phase Opposition Disposition (POD) strategy, Alternate Phase Opposition Disposition (APOD) strategy, hybrid strategy (PD and PS) and Phase Shift (PS) strategy. The study will help to choose those techniques with reduced harmonics for the chosen three phase cascaded MLI with R-L load. The Total Harmonic Distortion (THD), VRMS (fundamental), crest factor and form factor are evaluated for various modulation indices at two different switching frequencies (3.15KHz and 6 KHz). Simulation is performed using MATLAB-SIMULINK. It is observed that HYBRID PWM and PSPWM methods provide output with relatively low distortion for low and high switching frequencies. PODPWM and PSPWM are found to perform better since they provide relatively higher fundamental RMS output voltage for 6 KHz and 3.15 KHz switching frequencies. The experimental result shows PSPWM provide output with low distortion and HYBRID PWM provide output with higher fundamental RMS voltage for fc=3.15KHz. The experimental results were obtained only for fc=3.15KHz.


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